diff --git a/DroneModels b/DroneModels
index 29a12f3..bf57da0 160000
--- a/DroneModels
+++ b/DroneModels
@@ -1 +1 @@
-Subproject commit 29a12f35a75f3379a2824f3947304fdca7ea9a80
+Subproject commit bf57da01e55e3591b58702f14106d68ceea95765
diff --git a/OpenAthenaIOS.xcodeproj/project.pbxproj b/OpenAthenaIOS.xcodeproj/project.pbxproj
index 075da21..4ee1dc8 100644
--- a/OpenAthenaIOS.xcodeproj/project.pbxproj
+++ b/OpenAthenaIOS.xcodeproj/project.pbxproj
@@ -207,10 +207,10 @@
 			isa = PBXGroup;
 			children = (
 				59BEF5E92AB61C3700D5A56D /* OpenAthenaIOSRelease.entitlements */,
-				59A2554C2AB4A5C5009EB5BC /* OpenAthenaIOS.entitlements */,
-				596E92782AA7B090003E35CD /* droneModels.json */,
 				597089DA2A3FD35600B5E1BF /* Cubic.swift */,
+				59A2554C2AB4A5C5009EB5BC /* OpenAthenaIOS.entitlements */,
 				597089DB2A3FD35600B5E1BF /* EGM96complete.bin */,
+				596E92782AA7B090003E35CD /* droneModels.json */,
 				597089DC2A3FD35600B5E1BF /* EGM96Geoid.swift */,
 				59DBFF0F2AD0C456003C4B33 /* FisheyeDistortionCorrector.swift */,
 				59DBFF112AD0C48A003C4B33 /* PerspectiveDistortionCorrector.swift */,
@@ -708,7 +708,7 @@
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = AccentColor;
 				CODE_SIGN_ENTITLEMENTS = OpenAthenaIOS/OpenAthenaIOS.entitlements;
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 787;
+				CURRENT_PROJECT_VERSION = 842;
 				DEVELOPMENT_TEAM = S9737SV7NZ;
 				GENERATE_INFOPLIST_FILE = YES;
 				INFOPLIST_FILE = OpenAthenaIOS/Info.plist;
@@ -726,7 +726,7 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				MARKETING_VERSION = 2.50;
+				MARKETING_VERSION = 2.52;
 				NEW_SETTING = "";
 				PRODUCT_BUNDLE_IDENTIFIER = com.openathena.OpenAthenaIOS;
 				PRODUCT_NAME = OpenAthena;
@@ -745,7 +745,7 @@
 				ASSETCATALOG_COMPILER_GLOBAL_ACCENT_COLOR_NAME = AccentColor;
 				CODE_SIGN_ENTITLEMENTS = OpenAthenaIOS/OpenAthenaIOSRelease.entitlements;
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 787;
+				CURRENT_PROJECT_VERSION = 842;
 				DEVELOPMENT_TEAM = S9737SV7NZ;
 				GENERATE_INFOPLIST_FILE = YES;
 				INFOPLIST_FILE = OpenAthenaIOS/Info.plist;
@@ -763,7 +763,7 @@
 					"$(inherited)",
 					"@executable_path/Frameworks",
 				);
-				MARKETING_VERSION = 2.50;
+				MARKETING_VERSION = 2.52;
 				NEW_SETTING = "";
 				PRODUCT_BUNDLE_IDENTIFIER = com.openathena.OpenAthenaIOS;
 				PRODUCT_NAME = OpenAthena;
@@ -781,7 +781,7 @@
 			buildSettings = {
 				BUNDLE_LOADER = "$(TEST_HOST)";
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 787;
+				CURRENT_PROJECT_VERSION = 842;
 				DEVELOPMENT_TEAM = S9737SV7NZ;
 				GENERATE_INFOPLIST_FILE = YES;
 				IPHONEOS_DEPLOYMENT_TARGET = 14.0;
@@ -801,7 +801,7 @@
 			buildSettings = {
 				BUNDLE_LOADER = "$(TEST_HOST)";
 				CODE_SIGN_STYLE = Automatic;
-				CURRENT_PROJECT_VERSION = 787;
+				CURRENT_PROJECT_VERSION = 842;
 				DEVELOPMENT_TEAM = S9737SV7NZ;
 				GENERATE_INFOPLIST_FILE = YES;
 				IPHONEOS_DEPLOYMENT_TARGET = 14.0;
diff --git a/OpenAthenaIOS.xcodeproj/xcshareddata/xcschemes/OpenAthenaIOSTests.xcscheme b/OpenAthenaIOS.xcodeproj/xcshareddata/xcschemes/OpenAthenaIOSTests.xcscheme
index 6e6cd86..279dad1 100644
--- a/OpenAthenaIOS.xcodeproj/xcshareddata/xcschemes/OpenAthenaIOSTests.xcscheme
+++ b/OpenAthenaIOS.xcodeproj/xcshareddata/xcschemes/OpenAthenaIOSTests.xcscheme
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <Scheme
    LastUpgradeVersion = "1430"
-   version = "2.2">
+   version = "2.1">
    <BuildAction
       parallelizeBuildables = "YES"
       buildImplicitDependencies = "YES">
diff --git a/OpenAthenaIOS.xcworkspace/xcuserdata/rdk.xcuserdatad/UserInterfaceState.xcuserstate b/OpenAthenaIOS.xcworkspace/xcuserdata/rdk.xcuserdatad/UserInterfaceState.xcuserstate
index 42166b9..78dadef 100644
Binary files a/OpenAthenaIOS.xcworkspace/xcuserdata/rdk.xcuserdatad/UserInterfaceState.xcuserstate and b/OpenAthenaIOS.xcworkspace/xcuserdata/rdk.xcuserdatad/UserInterfaceState.xcuserstate differ
diff --git a/OpenAthenaIOS.xcworkspace/xcuserdata/rdk.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist b/OpenAthenaIOS.xcworkspace/xcuserdata/rdk.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist
index de65026..35b4777 100644
--- a/OpenAthenaIOS.xcworkspace/xcuserdata/rdk.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist
+++ b/OpenAthenaIOS.xcworkspace/xcuserdata/rdk.xcuserdatad/xcdebugger/Breakpoints_v2.xcbkptlist
@@ -14,8 +14,8 @@
             filePath = "OpenAthenaIOS/DroneImage.swift"
             startingColumnNumber = "9223372036854775807"
             endingColumnNumber = "9223372036854775807"
-            startingLineNumber = "1353"
-            endingLineNumber = "1353"
+            startingLineNumber = "1357"
+            endingLineNumber = "1357"
             landmarkName = "resolveTarget(dem:altReference:)"
             landmarkType = "7">
          </BreakpointContent>
diff --git a/OpenAthenaIOS/AboutViewController.swift b/OpenAthenaIOS/AboutViewController.swift
index 81cf1fa..9214431 100644
--- a/OpenAthenaIOS/AboutViewController.swift
+++ b/OpenAthenaIOS/AboutViewController.swift
@@ -168,8 +168,11 @@ class AboutViewController: UIViewController, UIScrollViewDelegate {
     // we want
     private func setTextViewText(htmlStr hString: String)
     {
-        if let attribString = vc.htmlToAttributedString(fromHTML: hString) {
-            self.textView.attributedText = attribString
+        // re issue #37, run entire on dispatchqueue
+        DispatchQueue.main.async {
+            if let attribString = self.vc.htmlToAttributedString(fromHTML: hString) {
+                self.textView.attributedText = attribString
+            }
         }
     }
     
diff --git a/OpenAthenaIOS/DebugViewController.swift b/OpenAthenaIOS/DebugViewController.swift
index abcc752..9f1f670 100644
--- a/OpenAthenaIOS/DebugViewController.swift
+++ b/OpenAthenaIOS/DebugViewController.swift
@@ -98,7 +98,7 @@ class DebugViewController: UIViewController, UIScrollViewDelegate {
         
         self.htmlString += "Coordinate system: \(app.settings.outputMode)<br>"
         self.htmlString += "Units: \(app.settings.unitsMode)<br>"
-        self.htmlString += "Drone params date: \(vc.droneParams!.droneParamsDate ?? "unknown"))<br>"
+        self.htmlString += "Drone params date: \(vc.droneParams!.droneParamsDate ?? "unknown")<br>"
         self.htmlString += "CCD data for \(vc.droneParams!.droneCCDParams.count) drones<br>"
         self.htmlString += "Use CCD Info: \(app.settings.useCCDInfo)<br>"
         self.htmlString += "EGM96 model loaded: \(EGM96Geoid.s_model_ok)<br>"
@@ -138,7 +138,7 @@ class DebugViewController: UIViewController, UIScrollViewDelegate {
             var centerLat,centerLon : Double
             (centerLat,centerLon) = vc.dem!.getCenter()
             
-            let urlStr = "https://maps.google.com/maps/search/?api=1&t=k&query=\(centerLat),\(centerLon)"
+            let urlStr = "https://www.google.com/maps/search/?api=1&t=k&query=\(centerLat),\(centerLon)"
             self.htmlString += "<a href='\(urlStr)'>\(urlStr)</a><br>"
         }
         else {
@@ -167,7 +167,7 @@ class DebugViewController: UIViewController, UIScrollViewDelegate {
                 var lon = try self.vc.theDroneImage!.getLongitude()
                 self.htmlString += "Latitude: \(lat)<br>"
                 self.htmlString += "Longitude: \(lon)<br>"
-                let urlStr = "https://maps.google.com/maps/search/?api=1&t=k&query=\(lat),\(lon)"
+                let urlStr = "https://www.google.com/maps/search/?api=1&t=k&query=\(lat),\(lon)"
                 self.htmlString += "<a href='\(urlStr)'>\(urlStr)</a><br>"
                 try self.htmlString += "Make: \(vc.theDroneImage!.getCameraMake())<br>"
                 try self.htmlString += "Model: \(vc.theDroneImage!.getCameraModel())<br>"
@@ -330,8 +330,11 @@ class DebugViewController: UIViewController, UIScrollViewDelegate {
     // we want
     private func setTextViewText(htmlStr hString: String)
     {
-        if let attribString = vc.htmlToAttributedString(fromHTML: hString) {
-            self.textView.attributedText = attribString
+        // re issue #37, run entire call on dispatchqueue main async
+        DispatchQueue.main.async {
+            if let attribString = self.vc.htmlToAttributedString(fromHTML: hString) {
+                self.textView.attributedText = attribString
+            }
         }
     }
     
diff --git a/OpenAthenaIOS/DroneImage.swift b/OpenAthenaIOS/DroneImage.swift
index 6bb89a2..bbf1ae2 100644
--- a/OpenAthenaIOS/DroneImage.swift
+++ b/OpenAthenaIOS/DroneImage.swift
@@ -606,10 +606,13 @@ public class DroneImage {
     // compass correction is merely to compensate for errors in drone's
     // compass calibration
     
-    public func getGimbalYawDegree() throws -> Double {
+    public func getGimbalYawDegree() throws -> Double 
+    {
         
         var az: Double
         
+        print("getGimbalYawDegree starting")
+        
         if metaData == nil {
             throw DroneImageError.NoMetaData
         }
@@ -620,6 +623,7 @@ public class DroneImage {
         }
         
         if metaData!["drone-dji:GimbalYawDegree"] != nil {
+            print("getGimbalYawDegree: drone-dji:GimbalYawDegree present")
             az = (metaData!["drone-dji:GimbalYawDegree"] as! NSString).doubleValue
             if settings != nil {
                 print("Adding \(settings!.compassCorrection) to AZ")
@@ -1558,7 +1562,9 @@ public class DroneImage {
     
     // parse XMP/XML data out of image throwing errors
     // if encountered
-    public func parseXmpMetaData() throws {
+    public func parseXmpMetaData() throws
+    {
+        print("parseXmpMetaData: starting")
         
         if rawData == nil {
             xmpDataRead = false
@@ -1575,14 +1581,14 @@ public class DroneImage {
         let beginRange = dataString.range(of: "<?xpacket begin")
         let endRange = dataString.range(of: "<?xpacket end.*?>", options: .regularExpression)
         if beginRange == nil || endRange == nil {
-            //print("parseXmpMetaData: did not find tags\n")
+            print("parseXmpMetaData: did not find tags\n")
             throw DroneImageError.NoXmpMetaData
         }
         let startIndex = beginRange!.lowerBound
         let endIndex = endRange!.upperBound
         xmlString = String(dataString[startIndex..<endIndex])
         print("XML doc length is \(xmlString!.count)")
-        //print("XML String to parse is \(xmlString!)")
+        print("XML String to parse is \(xmlString!)")
         
         // xmlString gets consumed by parser; we should parse a copy of it
         xmlStringCopy = xmlString
diff --git a/OpenAthenaIOS/LoadCalculateViewController.swift b/OpenAthenaIOS/LoadCalculateViewController.swift
index 042b365..7611c23 100644
--- a/OpenAthenaIOS/LoadCalculateViewController.swift
+++ b/OpenAthenaIOS/LoadCalculateViewController.swift
@@ -110,6 +110,9 @@ class LoadCalculateViewController: UIViewController,
         
         if vc.theDroneImage != nil {
             imageView.image = vc.theDroneImage?.theImage
+            // mark the image as its already been selected previously
+            // re issue #35
+            markImagePixel(x_prop: vc.theDroneImage!.targetXprop, y_prop: vc.theDroneImage!.targetYprop)
         }
         
         contentView.addSubview(stackView)
@@ -140,6 +143,12 @@ class LoadCalculateViewController: UIViewController,
                 
     } // viewDidLoad
     
+    // re issue #36, don't forget this function so that we can pinch/zoom
+    // the image
+    func viewForZooming(in scrollView: UIScrollView) -> UIView? {
+        return contentView
+    }
+    
     // when view is set to appear, reset the htmlString
     // if we go forward to calculate then back to selectImage,
     // viewDidLoad may not be called again and then we
@@ -148,6 +157,8 @@ class LoadCalculateViewController: UIViewController,
     {
         super.viewWillAppear(animated)
         
+        print("LoadCalculateViewController: viewWillAppear starting")
+        
         // create a cursor on target sender and pass Athena settings
         cotSender = CursorOnTargetSender(params: app.settings)
         
@@ -440,6 +451,8 @@ class LoadCalculateViewController: UIViewController,
     {
         var lat, lon: Double
         
+        print("getImageData: starting")
+        
         if vc.theDroneImage == nil {
             return
         }
@@ -486,9 +499,11 @@ class LoadCalculateViewController: UIViewController,
             }
         }
         catch {
-            self.htmlString += "Drone altitude: \(error)<br>"
+            self.htmlString += "Drone altitude: \(error)<br>" 
         }
         
+        print("getImageData: done, going to setTextViewText")
+        
         // display the text finally!
         setTextViewText(htmlStr: self.htmlString)
         
@@ -499,8 +514,13 @@ class LoadCalculateViewController: UIViewController,
     // we want
     private func setTextViewText(htmlStr hString: String)
     {
-        if let attribString = vc.htmlToAttributedString(fromHTML: hString) {
-            self.textView.attributedText = attribString
+        // to avoid crashing due to NSInternalConsistencyException, don't set
+        // on calling thread; dispatch to main async
+        // re issue #37
+        DispatchQueue.main.async {
+            if let attribString = self.vc.htmlToAttributedString(fromHTML: hString) {
+                self.textView.attributedText = attribString
+            }
         }
     }
     
@@ -603,6 +623,8 @@ class LoadCalculateViewController: UIViewController,
         // check for [ 0,0,0,0, 0,0,0,0, 0 ]
         // internally, all distances/altitudes are in meters
         
+        print("resolveTarget returned \(target)")
+        
         if target == [ 0.0, 0.0, 0.0, 0.0,  0.0, 0.0, 0.0, 0.0,  0.0] {
             print("doCalculations: target return values all zeros, returning")
             setTextViewText(htmlStr: htmlString)
@@ -623,14 +645,12 @@ class LoadCalculateViewController: UIViewController,
         target[8] = target[3] + offset
         
         //let nearestAltStr = roundDigitsToString(val: target[4] + offset, precision: 6)
-        
-        print("resolveTarget returned \(target)")
-        
+                
         //htmlString += "<h2>Target Lat,Lon: \(latStr),\(lonStr)</h2><br>"
         
         //htmlString += "Resolve target: \(target)<br>"
         //let urlStr = "https://maps.../maps/@?api=1&map_action=map&center=\(target[1]),\(target[2])"
-        let urlStr = "https://maps.google.com/maps/search/?api=1&t=k&query=\(latStr),\(lonStr)"
+        let urlStr = "https://www.google.com/maps/search/?api=1&t=k&query=\(latStr),\(lonStr)"
         htmlString += "<a href='\(urlStr)'><h2>Lat,Lon: \(latStr),\(lonStr)</h2></a><br>"
         if app.settings.unitsMode == .Metric {
             htmlString += "<h2>Alt: \(altStr)m</h2><br>"
@@ -685,7 +705,7 @@ class LoadCalculateViewController: UIViewController,
             
             let mgrsStr = MGRSGeodetic.WGS84_MGRS1m(Lat: target[1],Lon: target[2],Alt: target[3])
             //htmlString += "<h2>MGRS1m: \(mgrsStr)</h2><br>"
-            let urlStr = "https://maps.google.com/maps/search/?api=1&t=k&query=\(mgrsStr)"
+            let urlStr = "https://www.google.com/maps/search/?api=1&t=k&query=\(mgrsStr)"
             htmlString += "<a href='\(urlStr)'><h2>MGRS1m: \(mgrsStr)</h2></a><br>"
             if app.settings.unitsMode == .Metric {
                 htmlString += "<h2>Alt: \(altStr)m</h2><br>"
@@ -761,6 +781,8 @@ class LoadCalculateViewController: UIViewController,
             htmlString += "Altitude: above ground<br>"
         }
         
+        print("doCalculations: going to get image data")
+        
         getImageData()
                 
         setTextViewText(htmlStr: htmlString)
diff --git a/OpenAthenaIOS/SettingsViewController.swift b/OpenAthenaIOS/SettingsViewController.swift
index 3add7ac..80f353c 100644
--- a/OpenAthenaIOS/SettingsViewController.swift
+++ b/OpenAthenaIOS/SettingsViewController.swift
@@ -74,7 +74,7 @@ class SettingsViewController: UIViewController, UIScrollViewDelegate {
         // set slider parameters; keep consistent with OAAndroid
         newAZCorrection = app.settings.compassCorrection
         newAZSliderValue = app.settings.compassSliderValue
-        azOffsetLabel.text = "Manual Azimuth Correction \(newAZCorrection)"
+        azOffsetLabel.text = "Manual Azimuth Correction: \(newAZCorrection) \u{00B0}"
         azOffsetLabel.textAlignment = .center
         //azOffsetValueLabel.text = "\(newAZCorrection)"
         azOffsetSlider.minimumValue = 0.0
@@ -210,7 +210,7 @@ class SettingsViewController: UIViewController, UIScrollViewDelegate {
         newAZCorrection = 0.0
         azOffsetSlider.value = 100.0
         //azOffsetValueLabel.text = "Manual Azimuth Correction: \(newAZCorrection)"
-        azOffsetLabel.text = "Manual Azimuth Correction: \(newAZCorrection)"
+        azOffsetLabel.text = "Manual Azimuth Correction: \(newAZCorrection) \u{00B0}"
     }
     
     // user changed value via slider
@@ -221,7 +221,8 @@ class SettingsViewController: UIViewController, UIScrollViewDelegate {
         newAZCorrection = calculateAZCorrectionOffset(sliderValue: newAZSliderValue)
         //correctionTextField.text = "Manual Azimuth Correction: \(newCompassCorrection)"
         //azOffsetValueLabel.text = "\(newAZCorrection)"
-        azOffsetLabel.text = "Manual Azimuth Correction: \(newAZCorrection)"
+        // re issue #35, add colon and degree symbol
+        azOffsetLabel.text = "Manual Azimuth Correction: \(newAZCorrection) \u{00B0}"
     }
     
     // user changed value via text view
@@ -328,7 +329,7 @@ extension SettingsViewController: UIPickerViewDelegate {
 //        newCompassCorrection = app.settings.compassCorrection
 //        newCompassSliderValue = app.settings.compassSliderValue
 //        compassOffsetLabel.text = "Manual Azimuth Correction"
-//        compassOffsetValueLabel.text = "\(newCompassCorrection)"
+//        compassOffsetValueLabel.text = "\(newCompassCorrection) \u{00B0}"
 //        compassOffsetSlider.minimumValue = 0.0
 //        compassOffsetSlider.maximumValue = 200.0
 //        compassOffsetSlider.value = newCompassSliderValue
diff --git a/OpenAthenaIOS/ViewController.swift b/OpenAthenaIOS/ViewController.swift
index 5746555..58be296 100644
--- a/OpenAthenaIOS/ViewController.swift
+++ b/OpenAthenaIOS/ViewController.swift
@@ -12,7 +12,7 @@ import UIKit
 class ViewController: UIViewController {
     
     var app: AppDelegate = UIApplication.shared.delegate as! AppDelegate
-    var version: Double = 2.50
+    var version: Double = 2.52
     @IBOutlet var textView: UITextView!
     @IBOutlet var imageView: UIImageView!
     var dem: DigitalElevationModel?
@@ -283,8 +283,11 @@ class ViewController: UIViewController {
     // we want
     private func setTextViewText(htmlStr hString: String)
     {
-        if let attribString = htmlToAttributedString(fromHTML: hString) {
-            self.textView.attributedText = attribString
+        // re issue #37, run all of this on dispatchqueue main
+        DispatchQueue.main.async {
+            if let attribString = self.htmlToAttributedString(fromHTML: hString) {
+                self.textView.attributedText = attribString
+            }
         }
     }